Laravel Database Schema, Nullable Foreign

For laravel 7.x to create a nullable foreign key use simply:

$table->foreignId('country_id')->nullable()->constrained();

$table->foreignId('state_id')->nullable()->constrained();

REMEMBER: nullable should be before constrained otherwise the nullable will not be affected.

Set the country_id and the state_id nullable, like so.

$table->integer('country_id')->nullable()->unsigned();

$table->integer('state_id')->nullable()->unsigned();

With the latest version of Laravel, you can use the nullable method in conjunction of foreignKey:

$table
      ->foreignId('other_table_id')
      ->nullable() // here
      ->references('id')
      ->on('other_table');

For Laravel 7.x I use this way:

$table->bigInteger('word_type_id')->nullable()->unsigned();
$table->index('word_type_id')->nullable();
$table->foreign('word_type_id')->nullable()->references('id')->on('word_types')->onDelete('cascade');